The Relationship Between the Density of Cancer-Associated Fibroblasts in the Peritumoral Stroma and Clinicopathological Data in Breast Cancer Patients

During the routine marking before neoadjuvant chemotherapy of breast cancer patients with triple-negative, HER2-positive, or Luminal B molecular subtypes, the correlation between the density of cancer-associated fibroblasts in the samples taken from the center of the tumor and the peritumoral stroma of the same mass with the patient's clinical prognosis and pathological data will be examined.

Approach and Methods:

Collection of Tissue Samples via Core Needle Biopsy from Breast Cancer Patients (Luminal B, HER2 Group, and Triple-Negative Group):

Breast masses will be examined supine using an ultrasound machine with a 14 MHz linear transducer. The tumor and peritumoral parenchyma will be evaluated using a 1.5 T MRI machine with a 16-channel breast coil, in the prone position, under dynamic contrast-enhanced and diffusion-weighted imaging guidance. Under sonographic guidance and local anesthesia, one tissue sample will be taken from the center of the mass using a 14G/10 cm core needle immediately before marking for neoadjuvant chemotherapy. One tissue sample will be taken from the peritumoral stroma where diffusion restriction is shown in diffusion-weighted MRI from patients diagnosed with Luminal B, HER2, or triple-negative malignancy.

Identification of Cancer-Associated Fibroblasts via Immunohistochemical Analysis:

For immunohistochemical analysis, 3 µm thick sections will be taken from paraffin blocks prepared from the core needle biopsy tissues from the periphery of the tumor, and the blocks will be deparaffinized in an incubator at 60 °C. The prepared slides will be stained using the LEICA Bond III fully automated IHC system, with the FAPα antibody, SMA antibody, and PDGFR-β antibody. Diaminobenzidine (DAB) will be used as the chromogen. Positive control tissues will include Fibroblast Activation Protein, alpha [SP325] Conc. 0.1mL (1:100) colon adenocarcinoma, Actin Smooth Muscle [1A4] Conc. 0.1mL (1:100-500) appendix, and PDGFR-B [D-6] C.Liq.1ml (1:50-500) kidney.

The immunohistochemical analysis of the patient under clinical follow-up will be compared with the type of surgery performed, the pathological data, and the clinical prognosis.

Inclusion criteria

• Patients diagnosed with histopathologically confirmed Luminal B, HER2-positive, or triple-negative breast cancer subtypes.
• Patients who have not previously received any neoadjuvant chemoradiotherapy.
• Patients over 18 years of age.
• Adequate cellularity in biopsies obtained via core needle biopsy.

Exclusion criteria

• Patients diagnosed with histopathologically confirmed Luminal A breast cancer subtype.
• Patients who have previously received any neoadjuvant chemoradiotherapy.
• Patients under 18 years of age.
• Inadequate cellularity in biopsies obtained via core needle biopsy.